1. Field of the invention
The invention relates to a manufacturing process for an electrical contact part comprising a contact finger made of highly conductive material, particularly copper, onto which a coating in the form of a silver-based foil or strip constituting the contact is fixed by brazing or welding.
2. Description of the Prior Art
The choice of materials and of the surface of an electrical contact, particularly a switchgear contact, depends on many factors, and in particular on the resistivity of the contact material, the mechanical resistance and the arc-resistance of the contact, a contact pad of the kind mentioned, produced by welding a silver or silver alloy pellet onto a copper body enables these imperative requirements to be taken into account. The pellet, made for example of a silver-nickel alloy, is relatively thick, and its surface presents the definitive shape of the contact, for example curved or cylindrical. The body, in this case the contact finger, presents a foundation onto which the pellet is welded, notably by high frequency welding. The pellet and body keep their initial shape, the weld merely creating a simple bond therebetween.
This known process for producing a contact is costly for it necessitates a large amount of silver, which is a precious metal, and a relatively long welding or brazing time. Moreover, the whole end of the contact finger is subjected to annealing which affects its properties.